Semiconductor Active Pattern Uniformity via Layout Density Control
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Solution Overview
Problem
Current semiconductor device fabrication methods face challenges in achieving uniformity and improved electrical characteristics due to variations in pattern density and spacing, which affect the formation of active patterns on substrates.
Innovation Solution
A method involving the extraction of low-density regions on layouts, forming specific patterns that extend parallel to each other, and using these patterns to create active patterns on substrates through photolithography and etching processes, ensuring uniformity and improved electrical characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional photolithography is used to form patterns on substrates, then fabrication process is simple, but pattern uniformity and electrical characteristics deteriorate due to density variations
Solution Approach 1:
The fabrication process is segmented into multiple sequential steps: forming first patterns in a first photolithography step, forming second patterns in a second photolithography step, and selectively removing portions. This segmentation allows each step to focus on specific regions, improving overall pattern uniformity while managing complexity through structured progression
Solution Approach 2:
First patterns are formed in advance before the main active patterns are created. These preliminary first patterns serve as templates or guides that help control the formation of subsequent patterns, ensuring uniformity in the final structure while organizing the complex process into manageable stages
2Productivity
If patterns are placed densely to increase integration, then device functionality improves, but electrical characteristics worsen due to spacing variations
Solution Approach 1:
Different regions of the substrate receive different treatment through the sequential patterning process. First patterns are formed in specific regions, then second patterns are formed in relation to those first patterns, allowing local optimization of spacing and density to maintain electrical characteristics while achieving high integration
Solution Approach 2:
The process transitions from two-dimensional pattern placement to three-dimensional structural development by forming patterns at different stages and selectively removing portions. This dimensional approach allows better control over spacing and electrical characteristics while maintaining high integration density
3Area of moving object
If pattern spacing is reduced to increase device density, then integration improves, but manufacturing precision deteriorates due to spacing variations
Solution Approach 1:
First patterns are formed as preliminary structures before the main patterning step. These first patterns establish a foundation that guides subsequent pattern formation, ensuring consistent spacing even when patterns are closely spaced to increase device area utilization
Solution Approach 2:
The first patterns act as intermediary structures between the photolithography process and the final active patterns. They mediate the spacing control by providing a reference framework that ensures manufacturing precision is maintained during the transition to higher device density
Data Source
AI summary
A method of fabricating a semiconductor device includes: (i) placing, on a first layout, first patterns that extend parallel to each other in a first direction and are spaced apart from each other in a second direction intersecting the first direction, (ii) extracting a low-density region on the first layout, (iii) defining an enclosure region that surrounds the first patterns, (iv) placing dot patterns on a second layout, (v) extracting, from the dot patterns, first dot patterns that overlap the low-density region and do not overlap the enclosure region, (vi) placing the extracted first dot patterns on the first layout, (vii) allowing the first dot patterns to extend in the first direction to form second patterns, and (viii) using the first and second patterns to respectively form first and second active patterns on a substrate.